Smokeless non-recovery type coke oven

ABSTRACT

Passageways in the walls of the coke oven conduct the partially burned distillation products from the space above the coal charge to the sole heating flues located under the oven floor. The partially burned distillation products are drawn from the sole heating flues to undergo complete combustion as they pass upwardly through an ignition chamber and thence downwardly through a second ignition chamber. A stack with a variable speed fan is used to control the draw on the coke oven and the exhaust to the atmosphere of the combustion product received from the ignition chambers.

United States Patent [191 MacDonald et a].

[ Oct. 14, 1975 SMOKELESS NON-RECOVERY TYPE COKE OVEN [76] Inventors: James E. NIacDonald, RD. 4, Box 93, Latrobe, Pa. 15650; Oliver K. Painter, 101 N. Church St., Mount Pleasant, Pa. 15666 22 Filed: Mar. 8, 1974 21 Appl. No.: 449,234

[52] U.S. Cl. 202/102; 202/211; 202/130;

[51] Int. Cl. Cl0b 3/00; ClOb 5/00; ClOb 9/00 [58] Field of Search 202/101, 102, 113, 114,

[56] References Cited UNITED STATES PATENTS 500,684 7/1893 Westcrmann 202/101 537,872 4/1895 Vannier 202/211 1,269,895 6/1918 Willinger 202/101 I I I I I I 3,462,346 8/1969 Keman 202/113 X Primary ExaminerNorman Yudkoff Assistant ExaminerD. Sanders Attorney, Agent, or FirmBrown, Murray, Flick & Peckham ABSTRACT Passageways in the walls of the coke oven conduct the partially burned distillation products from the space above the coal charge to the sole heating flues located under the oven floor. The partially burned distillation products are drawn from the sole heating flues to undergo complete combustion as they pass upwardly through an ignition chamber and thence downwardly through a second ignition chamber. A stack with a variable speed fan is used to control the draw on the coke oven and the exhaust to the atmosphere of the combustion product received from the ignition chambers.

10 Claims, 2 Drawing Figures I j///////// l/f /7 Q\ Patent Oct. 14,1975 Sheet 1 of2 3,912,597

SMOKELESS NON-RECOVERY TYPE COKE OVEN BACKGROUND OF THE INVENTION This invention relates to the production of coke in a non-recovery type of coke oven, and more particularly, to the use of ignition chambers for the complete combustion of distillation products produced during the coking process for the smokeless operation thereof.

As is known, there are two major methods for the manufacture of metallurgical coke. The earliest of these methods is a non-recovery type of process wherein air is admitted into the coking chamber in controlled amounts for the purpose of burning the volatile products during the destructive distillation of coal to generate heat for further distillation. During the coking process, the smoke and other unbumt volatile products are discharged into the atmosphere.

The second and more recentmethod for producing coke is known as a by-product or retort process wherein air is excluded from the coking chamber during the distillation process and all the volatile products liberated during the process are recovered as gas and other coal by-product chemicals. The actual coking process may be operated in an essentially smoke-free manner. Part of the distillation gases recovered as byproduct are burned to provide the necessary heat for continuing the coking process.

While the non-recovery process was originally the leading method for the manufacture of metallurgical coke, it was subsequently almost entirely replaced by the by-product process which, in addition to the coke yield, produced other valuable coal chemicals. In recent years, however, the by-product process has lost favor among many coke producers. This is due, among other reasons, to the fact that the by-product process is much more costly which has been offset in the past to a large extent by the return on sales of the byproducts to such an extent that coke was obtained at a relatively low net cost. In recent years coke producers have had difficulty disposing of recovered coal chemicals on a profitable basis, particularly since many of the same or equivalent chemicals are recovered in the refining of petroleum products and therefore the cost of producing coke by the by-product method can no longer be offset by the sale by by-products. One important aspect favoring the adoption of the recovery-type of coke ovens was the substantial elimination of smoke and other forms of pollution as compared with the nonrecovery type of coke oven.

The non-recovery type of coke oven is sometimes referred to as a beehive coke oven. Each of these ovens were about 12 feet in diameter and had solid bottoms of floors. The ovens were built adjacent each other forming batteries. Coke was pulled from the ovens on alternate days so that heat from the side walls of a hot coke oven would ignite the coal in a newly-charged adjacent oven. The cycle for the production of coke by each oven was about 72 hours. The non-recovery process has again become an important factor to the coke industry, particularly in light of the more favorable economics. Not only is the coking process less costly, but also non-recovery coke ovens can be built at remote coal mine locations from where the coke can be shipped at less cost to facilities using coke, such as steel mill blast furnaces. The current non-recovery type of coke ovens offered in the industry are highly mechanized and embody rectangularly-shaped oven chambers; however the emission from the known designs of such ovens present monumental environmental prob lems that render them unacceptable for operation without causing hazardous pollution.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a coke producing apparatus of the non-recovery type to carry out the coking process in an accelerated manner without contaminating the atmosphere or surrounding area with distillation products arising out of the coking process.

It is another object of the present invention to provide an improved non-recovery type of coke oven apparatus wherein partially burned distillation products are used as an external supply of heat applied to the floor of the coke oven chamber and then conducted through an ignition chamber means for complete combustion of all partially burned distillation products so that harmless combustion products from the ignition chamber means can be discharged to the atmosphere by a stack.

In one form of the present invention, there is provided a coke producing apparatus comprising means for forming an oven chamber including side walls, an oven roof carried by the side walls, removable door means for the discharge of coke from the oven chamber and a floor to support a coal charge introduced into the oven chamber through an opening in the roof; means defining at least one passageway for conducting partially burned distillation products beneath the floor of the oven chamber in heat conducting contact therewith, means for conducting partially burned distillation products from the space above the coal charge in the oven chamber to the passageway beneath the floor, ig-

nition chamber means for essentially complete combustion of partially burned distillation products received from the passage beneath the floor, and a stack communicating with the ignition chamber means to draw products of combustion therefrom for exhaust to the atmosphere.

In the preferred form the ignition chamber means includes first and second ignition chambers arranged in end-to-end relation such that gases received from the floor beneath the coke oven chamber pass in one direction through one of the ignition chambers and then in the opposite direction through the other ignition chamber.

These features and advantages of the present invention as well as others will be more readily apparent when the following description is read in light of the accompanying drawings, in which:

FIG. 1 is an elevational view, in section, of a coke producing apparatus according to the present invention; and

FIG. 2 is a plan view, in section, taken along line II--II of FIG. 1. I

With reference to FIGS. 1 and 2 of the drawings,

there is illustrated two adjacent coke oven chambers 1 l and 12. The structure defining each coke oven chamber includes upstanding side walls 13 and 14 that are made of refractory brick or the like. An arched oven roof 15 is carried by the top surface of the side walls and spans the distance between them. One or more trunnel head openings 16 is formed in the oven roof depending upon the length of the oven chamber. Each of these openings is provided with a cast iron damper 17 which is removable to charge coal through an opening 16 into the oven chamber. A wall 18 closes one end of the oven chamber and upper and lower doors 19A and 198, respectively, close the opposite end of the oven chamber. These doors are removable to extract coke at the end of the coking process. The coke is supported in the oven chamber by a floor 21 that slopes in the downward direction from the wall 18 toward the doors, thereby to facilitate removal of the coke. The floor of the oven chamber is preferably made of silicon carbide or other refractory material of high heat conductivity. The floor 21 rests on a bed of silica tile 22 that is, in turn, supported by spaced-apart and parallel columns 23 that are arranged parallel to the side walls and form between them flue spaces 24 that are interconnected by a staggered arrangement of openings 23A in the columns. The flues 24 are used to extract residual heat from partially burned distillation products that are drawn out of the space above the coal charge in the oven chamber and flow through passageways 13A and 14A formed in the side walls 13 and 14, respectively. FIG. 2 illustrates two such passageways formed in each of the side walls. These passageways are continued through a portion of the roof for which purpose the parts of the roof directly supported by the side walls are made of castable refractory and having openings 15A formed therein for direct communication with the openings 13A and 14A in the side walls. As shown in FIG. 1, the openings 15A receive gases including the partially burned distillation products rising from the top of the coal charge in the oven chamber.

It is not a critical requirement of the present invention that two oven chambers such as illustrated in FIG. 1 be arranged in a side-by-side relation but when such an arrangement is employed which may typically form part of a battery of oven chambers, the oven chambers l 1 and 12 are spaced from each other in such a manner that a tandem arrangement of interconnected ignition chambers and 31 are located in an end-to-end relation between the side walls 14 of the chamber 11 and the side wall 13 of chamber 12. When such an arrangement is provided, the side walls of the oven chambers serving to form the ignition chambers have an additional thickness as compared with the thickness of the remaining side walls of the oven chambers. The ignition chambers 30 and 31 are each provided with a filling of checkerbrick 32 so as to provide an operating temperature in the ignition chambers of 2250F. Rider arches 33 for the chambers 30 and 31 span the distance between the side walls 13 and 14. Two parallel channels 35 and 36 interconnect the flues 24 and the ignition chamber 30. The partially burned distillation products are passed through these channels in a generally horizontal direction where they enter at the bottom of the ignition chamber 30 to pass in an upward direction through the open spaces in the checkerbrick. Thus, chamber 30 may be referred to as an up-pass chamber.

An arched roof 37 forms a gas flow space 38 above the checkerbrick in the ignition chambers 30 and 31. The roof is preferably of the type known as a bung roof and in its essential aspect consists of refractory bricks fitted into a cast iron frame. The roof can be lifted and removed for cleaning and replacing checkerbricks which form vertical flow spaces in the ignition chambers. A wall 39 separates the two ignition chambers and the gases passing upwardly through chamber 30 pass through space 38 and over the upper edge of this wall into chamber 31 which draws the gases in a downward direction and thus is referred to as a downpass ignition chamber. The partially burned distillation products entering the ignition chambers are completely burned therein and the residual combustion products are drawn off from the bottom of the down-pass ignition chamber 31 through a passageway 40 by a stack 41. A variable speed fan 42 is provided in the stack to control the flow of gases in the stack and therefore the flow of gases through the ignition chambers. This also controls the withdrawal of gases from the flues 24 beneath the floor of the coke chambers and the draw on the coke ove'n chamber itself.

In operation, the coke chambers 11 and 12 are charged with coal as soon as practical after drawing coke therefrom in order that the stored up heat from the previous coking process will be sufficient to start the next coking process. With the oven in readiness for charging, the cover 17 is removed from the opening 16 and the charge of coal is dropped through the openings leaving the coal in one or more cone-shaped piles underlying the charging openings. Thus, when two charging openings are provided, two cone-shaped piles will be formed in a given coke oven chamber. In order to secure uniform coking of the coal, the coal charge must be leveled so that the coal will lie in a bed of uniform thickness above the floor. Usually, the thickness of the coal charge is about 36 inches. To accomplish such leveling, the oven door 19B is closed in position to permit a leveling machine to level out the coal into the layer of uniform thickness, after leveling is completed, door 19A is closed. At the completion of the coking operation, both doors 19A and 19B are open and the coke is pulled out of the oven chamber.

In conventional prior art coke ovens, the coking process begins soon after leveling is completed, since the ovens retain enough heat in the brick of the walls to start liberation of volatile matter from the coal. As more heat is absorbed by the coal charge, the temperature of the oven soon reaches the ignition point of the volatile gases which, in the presence of air admitted to the oven, ignite and continue to burn quietly in the crown of the oven, or as small candle-like flames at the surface of the coal mass, thus applying heat to continue the process. It will be appreciated, therefore, that in prior art coke ovens, coking proceeds from the top of the coal downwardly, meaning that the coking time depends mainly on the depth of the coal. As a rule, it can be said that the coking process proceeds from the top downwardly at a rate of about one-half inch per hour. Assuming, therefore, that the depth of the coal within the oven is 3 feet, the entire coking process takes 72 hours or 3 days.

In accordance with the present invention, however, the hot gases formed by the partially burned distillation products are passed beneath the floor 21 of an oven chamber before they are withdrawn and passed through the ignition chambers. Thus, it can be seen according to the present invention, that coking process proceeds from the bottom of the coal upwardly as well as from the top downwardly, thereby materially increasing the speed of the coking process. Further, in accordance with the coke producing apparatus of the present invention, the coke ovens operate in a manner for the smokeless production of coke. A development which takes advantage of sole heating for the production of high grade coke at an accelerated rate. The gas conducting system for the partially'burned distillation products includes the use of two checker ignition chambers that remain at a constant operating temperature of approximately 2250F and burn all of the remaining residuals of distillation that are unburned in either the coke chamber or the sole heating flues 24. In order words, the double-pass ignition chamber system of the present invention provides a required additional residence time which coupled with an operating temperature of 2250 F in the checker ignition system, cause all products of combustion or distillation to be burned off as they reach this point on their way to the stack or common flue used for a battery of such ovens. Clean-out ports are provided at the bottom of the ignition chambers for the periodic removal of solids that are carried by the waste gases and fall or settle by gravity at the bottom of the ignition chambers. The use of a variable speed fan enhances the features of the present invention by providing an optimum draft or pressure on the coke oven chambers. When a battery of coke ovens are built using the features of the present invention, then, it is readily feasible to construct a main stack common to all coke chambers and running behind the entire battery of the oven chambers. Should additional cleaning of emission be required, then, a water spray section can be used for this purpose. The main stack would then have a variable speed fan. Alternatively, a venturi stack may be used.

The use of the ignition chambers of the present invention further enhances the coking process in regard to the need to quench the coke at the end of the process. Unlike by-product coke ovens which quench the coke outside the oven chambers and thereby create major environmental problems, the coke quenching process, according to the present invention, is carried out inside the ovens. For this purpose, spray pipes 50 are moved into the oven chamber through an opening provided by opening the door 19A. Water is then pumped through the pipes 50 to quench the coke. Essentially all the vapor, steam, etc. created during the quenching process remains in the oven chamber and pass through the sole heating flues and the checker ignition system where they undergo complete combustion. This eliminates the major environmental problems heretofore encountered in regard to quenching coke. The rectangular configuration of the coke oven chambers according to the present invention facilitates pulling or the extracting of coke from the oven chambers. This enhances the coke oven operation since straight side walls can be readily provided as opposed to the circular configuration of the beehive-type coke ovens in the past.

Although the invention has been shown in connection with a certain specific embodiment, it will be readily apparent to those skilled in the art that various changes in form and arrangement of parts may be made to suit requirements without departing from the spirit and scope of the invention.

We claim as our invention:

1. A coke producing apparatus comprising,

means for forming an oven chamber including side walls, an oven roof carried by the side walls, removable door means for the discharge of coke from the oven chamber, and a floor to support a coal charge introduced into the oven chamber through a closable opening in said roof,

means defining a sole heating flue including at least one passageway for conducting partially burned distillation products beneath said floor in heat conducting contact therewith,

means for conducting partially burned distillation products from the space above a coal charge in said oven chamber into said sole heating flue,

means defining a discharge flue arranged to receive the partially burned distillation products from said sole heating flue,

ignition chamber means having checkerbricks therein at the delivery side of said discharge flue and remote to said sole heating flue for essentially complete combustion of partially burned distillation products conducted from the space above the coal charge in the oven chamber through said sole heating flue and thence by said discharge flue into the ignition chamber means, and

a stack drawing combustion products from said ignition chamber means for exhaust to the atmosphere.

2. The apparatus according to claim 1 wherein said ignition chamber means includes a first ignition chamber for the combustion of partially burned distillation products while passing in one direction therethrough from said passageway, and a second ignition chamber for combustion of any remaining partially burned distillation products received from said first ignition chamber while passing in a direction opposite to the flow direction in said ignition chamber.

3. An apparatus according to claim 1 wherein said means for conducting partially burned distillation products includes a flue defined within at least one of said side walls.

4. An apparatus according to claim 3 wherein said roof includes an opening for conducting partially burned distillation products to a flue defined in a side wall of the coke chamber.

5. An apparatus according to claim 2 wherein said discharge flue is further defined to include an opening in one of said side walls for conducting partially burned distillation products from the sole heating flue to said first ignition chamber.

6. An apparatus according to claim 2 wherein said checkerbricks form flow spaces in each of said first and second ignition chambers for maintaining operating temperatures therein for the essential complete combustion of the partially burned distillation products.

7. An apparatus according to claim 6 further comprising a roof enclosing the top of said first and second ignition chambers for defining a flow space between said chambers above said checkerbricks.

8. An apparatus according to claim 1 further comprising variable speed fan means for controlling the flow of gases in said stack.

9. An apparatus according to claim 1 wherein said means defining a sole heating flue include a plurality of spaced apart and parallel columns supporting said floor of the oven chamber, and opening in said columns for interconnecting the spaces therebetween.

10. An apparatus according to claim 1 wherein said means forming an oven chamber are further defined to include:

parallel and spaced apart side walls;

an oven roof spanning the distance between the side walls; said oven roof having at least one closable charging opening;

a rectangular shaped floor to support a coal charge removable door means extending between the other 'mroduced through Chargmg openmg; ends of the side walls for the removal of coke from a wall extending between one of the ends of the side walls for defining one end wall of an oven chamber with a rectangular shape, and

the oven chamber. 

1. A COKE PRODUCING APPARATUS COMPRISING, MEANS FOR FORMING AN OVEN CHAMBER INCLUDING SIDE WALLS, AN OVEN ROOF CARRIED BY THE SIDE WALLS, REMOVABLE DOOR MEANS FOR THE DISCHARGE OF COKE FROM THE OVEN CHAMBER, AND A FLOOR TO SUPPORT A COAL CHARGE INTRODUCED INTO THE OVEN CHAMBER THROUGH A CLOSABLE OPENING IN SAID ROOF, MEANS DEFINING A SOLE HEATING FLUE INCLUDING AT LEAST ONE PASSAGEWAY FOR CONDUCTING PARTIALLY BURNED DISTILLATION PRODUCTS BENEATH SAID FLOOR IN HEAT CONDUCTING CONTACT THEREWITH, MEANS FOR CONDUCTING A PARTIALLY BURNED DISTILLATION PRODUCTS FROM THE SPACE ABOVE A COAL CHARGE IN SAID OVEN CHAMBER, INTO SAID SOLE HEATING FLUE, MEANS DEFINING A DISCHARGE FLUE ARRANGED TO RECEIVE THE PARTIALLY BURNED DISTILLATION PRODUCTS FROM SAID SOLE HEATING FLUE, IGNITATION CHAMBER MEANS HAVING CHECKERBRICKS THEREIN AT THE DELIVERY SIDE OF DISCHARGE FLUE AND REMOTE TO SAID SOLE HEATING FLUE FOR ESSENTIALLY COMPLETE COMBUSTION OF PARTIALLY BURNED DISTILLATION PRODUCTS CONDUCTED FROM THE SPACE ABOVE THE COAL CHARGE IN THE OVEN CHAMBER THROUGH SAID SOLE HEATING FLUE AND THENCE BY SAID DISCHARGE FLUE INTO THE IGNITION CHAMBER MEANS, AND A STACK DRAWING COMBUSTION PRODUCTS FROM SAID IGNITION CHAMBER MEANS FOR EXHAUST TO THE ATMOSPHERE.
 2. The apparatus according to claim 1 wherein said ignition chamber means includes a first ignition chamber for the combustion of partially burned distillation products while passing in one direction therethrough from said passageway, and a second ignition chamber for combustion of any remaining partially burned distillation products received from said first ignition chamber while passing in a direction opposite to the flow direction in said ignition chamber.
 3. An apparatus according to claim 1 wherein said means for conducting partially burned distillation products includes a flue defined within at least one of said side walls.
 4. An apparatus according to claiM 3 wherein said roof includes an opening for conducting partially burned distillation products to a flue defined in a side wall of the coke chamber.
 5. An apparatus according to claim 2 wherein said discharge flue is further defined to include an opening in one of said side walls for conducting partially burned distillation products from the sole heating flue to said first ignition chamber.
 6. An apparatus according to claim 2 wherein said checkerbricks form flow spaces in each of said first and second ignition chambers for maintaining operating temperatures therein for the essential complete combustion of the partially burned distillation products.
 7. An apparatus according to claim 6 further comprising a roof enclosing the top of said first and second ignition chambers for defining a flow space between said chambers above said checkerbricks.
 8. An apparatus according to claim 1 further comprising variable speed fan means for controlling the flow of gases in said stack.
 9. An apparatus according to claim 1 wherein said means defining a sole heating flue include a plurality of spaced apart and parallel columns supporting said floor of the oven chamber, and opening in said columns for interconnecting the spaces therebetween.
 10. An apparatus according to claim 1 wherein said means forming an oven chamber are further defined to include: parallel and spaced apart side walls; an oven roof spanning the distance between the side walls; said oven roof having at least one closable charging opening; a rectangular shaped floor to support a coal charge introduced through said charging opening; a wall extending between one of the ends of the side walls for defining one end wall of an oven chamber with a rectangular shape, and removable door means extending between the other ends of the side walls for the removal of coke from the oven chamber. 